Critical Illness in Patients with Multiple Sclerosis: A Matched Case-Control Study

BACKGROUND Over the course of multiple sclerosis (MS) several conditions may arise that require critical care. We aimed to study the reasons for admission and outcome in patients with MS admitted to a neuro-intensive care unit (NICU). METHODS We retrospectively searched the electronic charts of a 9-bedded NICU in a tertiary hospital for patients with a diagnosis of multiple sclerosis (MS) from 1993-2015, and matched them to NICU controls without MS based on age and gender. Conditional logistic regression was used to compare admission causes, Charlson's Comorbidity Index, indicators of disease severity, and survival between MS and non-MS patients. RESULTS We identified 61 MS patients and 181 non-MS controls. Respiratory dysfunction was the most frequent reason for NICU admission among MS patients (34.4%), having infectious context as a rule. In a matched analysis, after adjusting for co-morbidities and immunosuppressive medications, patients with MS were more likely to be admitted to the NICU because of respiratory dysfunction (OR = 7.86, 95% CI 3.02-20.42, p<0.001), non-respiratory infections (OR = 3.71, 95% CI 1.29-10.68, p = 0.02), had a higher rate of multiple NICU admissions (OR = 2.53, 95% CI 1.05-6.05, p = 0.04) than non-MS patients. Mortality after NICU admission at a median follow-up time of 1 year was higher in MS than control patients (adjusted OR = 4.21, 95% CI 1.49-11.85, p = 0.04). CONCLUSION The most common reason for NICU admission in MS patients was respiratory dysfunction due to infection. Compared to non-MS patients, critically ill MS patients had a higher NICU re-admission rate, and a higher mortality.